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  • Reexamining the Estimation of Tropical Cyclone Radius of Maximum Wind from Outer Size with an Extensive Synthetic Aperture Radar Dataset
Title: Reexamining the Estimation of Tropical Cyclone Radius of Maximum Wind from Outer Size with an Extensive Synthetic Aperture Radar Dataset
Abstract

The radius of maximum windRmax, an important parameter in tropical cyclone (TC) ocean surface wind structure, is currently resolved by only a few sensors so that, in most cases, it is estimated subjectively or via crude statistical models. Recently, a semiempirical model relying on an outer wind radius, intensity, and latitude was fit to best-track data. In this study we revise this semiempirical model and discuss its physical basis. While intensity and latitude are taken from best-track data,Rmaxobservations from high-resolution (3 km) spaceborne synthetic aperture radar (SAR) and wind radii from an intercalibrated dataset of medium-resolution radiometers and scatterometers are considered to revise the model coefficients. The new version of the model is then applied to the period 2010–20 and yieldsRmaxreanalyses and trends that are more accurate than best-track data. SAR measurements corroborate that fundamental conservation principles constrain the radial wind structure on average, endorsing the physical basis of the model. Observations highlight that departures from the average conservation situation are mainly explained by wind profile shape variations, confirming the model’s physical basis, which further shows that radial inflow, boundary layer depth, and drag coefficient also play roles. Physical understanding will benefit from improved observations of the near-core region from accumulated SAR observations and future missions. In the meantime, the revised model offers an efficient tool to provide guidance onRmaxwhen a radiometer or scatterometer observation is available, for either operations or reanalysis purposes.

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Award ID(s):
1945113
PAR ID:
10521565
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
American Meteorological Society
Date Published:
Journal Name:
Monthly Weather Review
Volume:
151
Issue:
12
ISSN:
0027-0644
Page Range / eLocation ID:
3169 to 3189
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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